Anti-Lock Braking System (ABS)
An anti-lock braking system (ABS) is a safety system that rapidly modulates brake pressure when one or more wheels approach lock during braking.
Why wheel lock matters
A locked wheel slides instead of rolling, reducing the tyre’s ability to generate the directional forces needed for steering. ABS uses wheel-speed sensors and a hydraulic or electromechanical controller to reduce and restore pressure repeatedly at affected wheels. The driver can usually keep pressing the brake pedal while the system works.
The main purpose is to preserve directional control and vehicle stability during hard braking. ABS can also help the vehicle use available tyre grip, but it does not guarantee a shorter stopping distance on every surface. Loose gravel, deep snow, ice, tyre condition, speed, and driver input all affect the outcome.
In an EV, regenerative braking and friction braking may be blended during ordinary deceleration. ABS responds to actual or imminent wheel slip and can reduce regenerative torque, apply friction-brake control, or coordinate both depending on the vehicle design. The brake pedal may pulse or make noise during intervention; this can be normal.
ABS does not create grip and cannot overcome physical limits. Safe speed, adequate following distance, suitable tyres, and driver attention remain essential.
For components, control logic, and EV brake blending, see Anti-Lock Braking System.